1. Field of the Invention
The present invention relates to systems and methods for computing head motion estimation from the facial image positions, e.g., eye and mouth corners, and, particularly, to a linear method for performing head motion estimation using four (4) facial feature points. As a special case, an algorithm for head pose estimation from four feature points is additionally described.
2. Discussion of the Prior Art
Head pose recognition is an important research area in human computer interaction and many approaches of head pose recognition have been proposed. Most of these approaches model a face with certain facial features. For example, most existing approaches utilize six facial feature points including pupils, nostrils and lip corners are used to model a face, while others, such as reported in the reference to Z. Liu and Z. Zhang entitled “Robust Head Motion Computation by Taking Advantage of Physical Properties”, Proc. Workshop on Human Motion, pp. 73–80, Austin, December 2000, implements five facial feature points including eye and mouth corners and the tip of the nose. In Zhang, the head motion is estimated from the five feature points through non-linear optimization. In fact, existing algorithms for face pose estimation are non-linear.
It would be highly desirable to provide a face pose estimation algorithm that is linear, and computationally less demanding than non-linear solutions.
It would be further highly desirable to provide a face pose estimation algorithm that is linear, and relies on only four feature points such as the eye and mouth corners.